Printing machine



A ril 3@, 1935. L T. NELSON PRINTING MACHINE Filed Aug. 1'7, 1934 2 Sheets-Sheet 1 April MD, 1935. 1. T. NELSON PRINTING MACHINE 2 Sheets-Sheet 2 Filed Aug. 17, 1954 I72 venhr,

Patented Apr. 30, 1935 1,999,776 PRINTING MAcmNE Ian Theodore Nelson, Edinburgh, Scotland Application August 17, 1934, Serial No. 740,334 7 V .In GreatBritain July 19, 1934 s Claims. (01. ml-'38s) This invention relates to improvements inthe registering arrangements used in printing machines in or modification of the and is an improvement invention forming the subject of my United States-Letters Patent No.

1g939,133 issued 12th December, 1933.

In the specification of the said Letters Patent there is described an arrangement comprising a flat bed presenting a surface formed with longi: tudinal guideways and adaptedfor the reception of series of printing plates deposited on said surface, parallel rows transverse to said guideways, parallel series of plate-engaging clamps interposed between adjacent rows of plates, said clamps being guided in said guideways for adjustment transversely of said rows of plates, and means including screw-spindles for transmitting pressure in the longitudinal direction of said bed through the entire series of plates and their clamps in any given guideway whereby to lock said series of plates to the surface of said bed.

As described in the specification of the said Letters Patent non-adjustable distance pieces were interposed between adjacent series of clamps so as to space adjacent rows of plates the requisite distance apart.

According to the present improvement, in lieu of said non-adjustable distance pieces, I interpose between adjacent series of clamps adjustable struts which may be pre-set to give the requisite inter-row spacing and which may be adjusted individually to effect independent adjustment of the plates after the entire series of plates and clamps have been locked up on the bed by the pressure-transmitting means.

The improved arrangement, permitting as it does independent micrometer adjustment of the plates, is of primary importance in connection with colour printing work.

The invention is illustrated in the accompanying drawings in which Fig. 1 is a fragmentary plan view, Fig. 2 a vertical section on the line a-a of Figs. 1 and 3, and Fig. 3 a vertical section on the line bb of Figs. 1 and 2, showing a plate registering arrangement in which each plate is held to the bed of the machine by means of two clamps; Fig. 4 is a fragmentary plan View showing a modified arrangement in which each' plate is held to the bed by means of two pairs of clamps, this arrangement being particularly suited to colour printing work.

As shown, I denotes the printing plates which are interposed in rows between series of plateengaging clamps 2 (Figs. 1-3) and 2 (Fig. 4) guided for adjustment transversely of the rows of for the printing plates plates and adapted to clamp the plates I in ready position under the action of pressure interacting between the plate rows in the direction transversely of said rows. 7

The printing plates. l are deposited upon a bed 3 which is reciprocated in the line T and which presents a plurality of :parallel spaced guideways 4 for'the clamps 2, 2, said guideways extending longitudinally of the. bed, i. e., parallel to the. line T of travel.

The clamps 2, 2 are freely slidable longitudinally of the bed, in engagement with the guideways 4, each clampqlfiengaging. two adjacent guideways 4, and each clamp 2 engaging one guideway 4.

The clamps present undercut plate-engaging 'faces 8 which are preferably serrated so as securely to lock the plates against lateral displacement.

!3 denotes a fixed abutment bar extending transversely along the front of the bed and I6 denotes a transverse pressure-bar extending along the rear or" the bed and adjustable towards and away from the bar I 3 by manipulation of screw-threaded spindles as H operable from the front of the bed.

In making ready, the printing plates I are deposited on the bed 3 in rows extending transversely of the guideways 4, each row of plates I being interposed between two series of clamps 2 (Fig. 1) or 2' (Fig. 4).

To space the clamps apart between the plate rows, I interpose between corresponding clamps of adjacent series of clamps struts each including a screw-threaded spindle 35 engaged by a nut 36 and provided at one end with a collar 3'! presenting radial sockets 33 engageable by a tommy bar or the like to effect rotation of the spindle 35. Beyond the collar 37 there is provided an unthreaded extension 35' of the spindle 35.

In the arrangement according to Figs. 1-3 each clamp 2 presents two sunk recesses 39, one depending into each guideway 4 engaged by the respective clamp, each such recess being adapted for reception of a spindle 35 or extension 35' of a strut, so as to support said strut within the confines of the relative guideway 4, below the level of the printing plates I. Each transverse row of struts is thus constituted of pairs of struts inter- 'posed between pairs of clamps of two adjacent 9 PTET OFFICE f '31 of each strut is pre-set by gauge according to the inter-row spacing of the printing plates I.

Simplified adjustable struts are interposed between the iront bar I3 and the foremost series of clamps and between the rear bar I6 and the rearmost series of clamps, each of saidfsimplified struts including a long nut 36 and a screwthreaded spindle unprovided with an extension In the arrangement according to Fig. 4 eachprinting plate I is held to the bed 3 by means of two pairs of clamps 2' engaging opposed edges of the plate, each clamp being located near one corner of the plate I, engaging one guideway 4 only, and presenting one sunk strut-supporting recess 39. As will be understood, the arrangement is such that each printing plate I may be adjusted angularly within small limits as well as bodily, thus facilitating the operation of making ready for colourprinting.

I claim:

1. In a printing machine, the combination of a surface presenting guideways and adapted for the reception of series of printing plates deposited on said surface in parallel rows transverse to said guideways, parallel series of plateengaging clamps interposed between adjacent rows of plates, said clamps being guided in said guideways for adjustment transversely of said rows of plates, individually adjustable struts interposed betweenadjacent series of clamps, each of said struts comprising a screw-threaded spindle, a collar unitary with said spindle presenting sockets engageable by a tommy bar to effect rotation of the spindle, and a nut engaging said spindle, said collar and nut constituting clampengaging abutments, screw spindles arranged beneath said clamps and extending longitudinally of said surface, and transverse pressure plate sections'h'aving nuts engaged by said screw spindles, said screw spindles and pressure plate sections serving as means for transmitting pressure through an entire series of plates and their clamps in any given guideway, whereby simultaneously to lock said plates to said surface.

-2. The combination claimed in claim 1 in which the clamps are provided with sunk recesses for reception of the struts below the level of the plates.

3. The combination claimed in claim 1 in which the struts are supported by the clamps below the level of the plates.

IAN THEODORE NELSON 

